BBC News understands the yacht had drifted towards the Admiral Grigorovich, a Russian frigate which has been operating in the Channel.
Related stories
Brazil's Supreme Court suspends permit for major Amazon gold mine
‘Umamusume’ concert cancellation highlights visa hurdles for Japanese performers
Ireland votes to end UN veto over overseas peacekeeping missions
Japanese films at TIFF feature melodrama, monsters and more
Trump hopes to flatter Putin into negotiating on Ukraine, experts say
One killed, eight injured in attack on Saudi Arabia’s King Fahd airport